Slaving system and method



Dec. 13, 1960 A. M. FUCHS SLAVING SYSTEM AND METHOD 4 Sheets-Sheet 1 Filed April 1. 1952 INVENTOR. ABRAHAM M- FUCHS ATTORNEY CE/V 7' SFO r N F0 ME CIRCUIT RE ER RAN RMER RA 5 R R 66 68 Y 5 P2 GATED 74 GATED /75 GATED 78 GATED AMPLIFIER AMPLIFIER AMPLIFIER AMPLIFIER Y Y Y Y DETECTOR DETECTOR DETECTOR 45 DETECTOR Y Y Y Y 66 SIGNAL RESOLVER /9o SIGNAL RESOLVER 91 F"' Y F' Y Y D/FFERENT/ATOR /9 Y D/FFERENT/ATOR 5 l Y '"*1 Y SERVOMECHA NIsIvI SERVO/MECHANISM //0o Dec. 13, 1960 A. M. FUCHS 2,964,266

SLAVING SYSTEM AND METHOD Filed April 1, 1952 4 Sheets-Sheet 2 TWO PHASE R /v A 7' NNA MODULATO MAG Ema/v A/\/ E \/6 ALTERNATOR56 RA NGE 6A TE IYYYIYL JIIIYIDIII AW m E & V m

V INVENTOR.

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A TTOR/VE Y Dec. 13, 1960 A. M. FUCHS SLAVING SYSTEM AND METHOD 4 Sheets-Sheet 3 Filed April 1. 1952 VT V INVENTOR. 45/01 HAM M, FUCHS A TTORNE v SLAVING SYSTEM AND METHOD Abraham M. Fuchs, New York, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Apr. 1, 1952, Ser. No. 279,721

9 Claims. 7 ci.244 4 V This invention relates to a System for positioning a missle antenna and more particularly to a system for pointing a missile antenna at a target before the missile is launched so that the missile will have as good a chance as possible of intercepting the target after it is launched.

In co-pending application Serial No. 175,442, filed July 22, 1950, by Edmund F. Lapham, Jr., and Ian H. McLaren, now abandoned, a system is disclosed for guiding a missile to intercept a target. The system is housed within the missile to actively guide the missile, without externalv controls, on a collision course towards the target. In a collision course, the missile gradually overtakes the missile along a line of sight between the missile and the target but merely follows the movement of the target in directions substantially perpendicular to the line of sight.

To maintain the missile on the proper course towards the target, the system disclosed in the co-pending application produces predetermined pivotal movements of the missile relative to its antenna, the missile being pivotable relative to the antenna in three substantially perpendicular planes. However, the missile has only a limited movement relative to its antenna in a predetermined one of the three planes. Because of this limited movement in the predetermined plane, the missile is pivoted relative to its antenna in a compensatory manner in the other two planes to provide a substitution for its movement in the predetermined plane. In this way, the missile antenna is maintained pointed at the target during flight by properly pivoting the missile when it deviates from a collision course.

Since the missile has only a limited movement in the predetermined plane, a problem is presented as to how to maintain the missile pointed at the target before it is launched. The problem is especially acute because the missile antenna must be pointed at the target to provide the missile with as good a chance as possible of intercepting the target after it has been launched. The problem of training the missile antenna on the target is presented because the movement of the missile antenna is determined before launching by an antenna housed in the interceptor from which the missile is launched. The interceptor antenna is constructed to have wide ranges of movement in all of the pivotal planes and is controlled in its movement by a radar system in the interceptor. Since the missile antenna has only a limited movement in the predetermined plane, it cannot follow the movement of the interceptor antenna in that plane.

This invention provides a system for converting deterinitiations made by the radar system housed in the interceptor into movements of the missile antenna in the two planes substanitally perpendicular to the plane of limited movement. The determinations of the radar system relate to the elevationa'l, or vertical, distance between the missile and the target at any instant and to the azimuthal, or horizontal, distance between the missile and the target at that instant. By converting the azimuth and elevation determinations of the radar system into pivotal move- 2,954,266 Patented Dec. 13, 1960 ments of the missile antenna in its planes of unlimited movement, the missile antenna is able to track with the interceptor antenna in pointing at the target before the missile is launched.

An object of this invention is to provide a system for maintaining the antenna of a missile pointed at a target before the missile is launched, so that the missile will have as good a chance as possible of intercepting the target.

Another object is to provide a system of the above character for converting determinations of a radar system as to the position of a target into appropriate movements of the missile antenna to maintain the antenna trained on the target before it is launched.

A further object is to provide a system of the above character for training a missile antenna on a target in accordance with the movements of a master antenna in an interceptor housing the missile, such training being produced by pivoting the missile antenna in different planes than the pivotal movement of the master antenna.

Still another object is to provide a system of the above character for operating in conjunction with a missile an tenna, before the missile is launched, to limit the relative movement between the missile and the antenna in a predetermined plane by providing compensatory movements of the antenna in planes substantially perpendicular to the predetermined plane.

Other objects and advantages will be apparent from a detailed description of the invention and from the appended drawings and claims.

In the drawings:

Figure 1 is a perspective view of a missile, including its antenna, and an interceptor for housing the missile before the missile is launched;

Figure 2 is an enlarged perspective view of important components forming a part of the missile antenna shown in Figure 1;

Figure 3 is a simplified block diagram of an electrical system for guiding the missile shown in Figure 2 on an optimum course towards a' distant target;

Figure 4 illustrates the pattern of the signals reflected from the target to the missile antenna when the missile deviates during flight from its optimum course towards the target;

Figure 5 shows curves illustrating the manner in which the signals shown in Figure 4 are utilized by the electrical system shown in Figure 3 to correct any deviations of the missile from its optimum course towards a target;

Figure 6 is an enlarged rear elevational view of the missile tail fins, showing the angle through which the missile may be rotated at any instant relative to its antenna to correct any deviations in its flight;

Figure 7 is a view illustrating in schematic form the beam radiated towards the target by the missile antenna shown in Figure 2;

Figure 8 is a schematic diagram illustrating the relative flight paths at any instant of the missile and the target after the missile has been launched;

Figure 9 illustrates the course adopted by the missile to intercept the target for a particular flight path of the target;

Figure 10 is a simplified block diagram of an electrical system for maintaining the missile antenna pointed at a target before the missile is launched;

Figure 11 is a spatial diagram schematically illustrating the manner in which the missile antenna is rotated before launching, in accordance with determinations as to the position of the missile relative to the target; and

Figure 12 is a view further illustrating geometrically the manner in which the system shown in Figure 10 op erates to train the missile antenna on the target.

In one embodiment of the invention, a missile, genported by an interceptor, generally indicated at 12, and to overtake a target, generally indicated at 14 (Figure 8), after being launched. The missile has an antenna, generally indicated at 16, the movement of which is determined before the missile launching by an antenna in a radar system 20 (Figure 10), as will be disclosed in detail hereafter. The radar system 20 forms part of the permanent equipment of the interceptor 12. One radar system which may be used has been given the engineering designation of AN/APQ35. The construction and operation of the AN/APQ-35 radar system are fully disclosed in Handbook of Maintenance Instructions for Radar Sets AN/APQ-35 and AN/APQ- 35A (three volumes), published in 1950 under the authority of the Secretary of the Air Force and the Chief of the Bureau of Aeronautics.

- --In addition to the antenna 16, which is positioned at its forward end, the missile has an electrical system, partly shown in Figure 3 and partly in Figure 10, at an intermediate position and also has an'explosive charge at its rear end. A first pair of diametrically disposed, outwardly extending fins 24 (Figures 1 and 6) is positioned at an intermediate position in the missile 10 and is adapted to be pivoted relative to the missile to alter the course of the missile in one direction. A second pair of diametrically disposed fins 26 is positioned at an intermediate position in the missile in quadrant relationship to the fins 24 and in pivotal relationship to the missile to alter the course of the missile in a direc tion substantially perpendicular to that controlled by the fins 24.

The construction and operation of the antenna 16 is disclosed in detail in co-pending application Serial No. 212,151, filed February 21, 1951, by Theodore M. Mategorin, now abandoned. It includes a mount gimbal 28, a ring'gimbal 30 and a horseshoe gimbal 32. The mount gimbal is adapted to rotate on a spindle relative to the missile and to be driven through a suitable gear train by a motor 34. The ring gimbal 30 is pivotably mounted on stanchions 36 extending from the mount gimbal 34 and is adapted to retain in a socket the rotor of a synchro 38, the stator of which is supported by one of the stanchions.

A segment 40 of a ring gear extends from the periphery of the ring gimbal 30 and, before the release of the missile, meshes with a gear train by a motor (not shown), the motor being connected to the synchro 38. A solenoid 42 controls the position of a pinion gear 44 in the gear train and, when energized, actuates its armature to move the pinion gear 44 out of mesh with the ring gear 40.

. The horseshoe gimbal 32 is suitably mounted on the ring gimbal 30 in pivotable relationship to the ring gimbal and is adapted to carry the rotor of a synchro 48, the stator of which is mounted in a socket of the ring gimbal. The synchro 48 is electrically connected to the motor 34 so as to operate the motor during flight when an error signal is produced in it as a result of a pivotable movement of the horseshoe gimbal 32 relative to the ring gimbal.

A shaft 50 is supported by the horseshoe gimbal 32 at its inner end, and a wave guide 52 is in turn suitably secured to the outer end of the shaft in aligned relationship with the shaft. The stators of a motor 54 and of an alternator 56 are mounted on the shaft, and the rotors-of the motor 54 and the alternator 56 are suitably secured to a retainer 58 adapted to rotate on bearings relative to the shaft 50. An annular reflector 60 having aparabolic shape in axial cross-section is suitably secured to the retainer 58, with its axis tilted in slightly skewed relationship tothe shaft 50. The retainer 58, the alternator 56 and the reflector 60 are driven by the motor 54 at a substantially constant speed. Because of this relatively high speed of rotation, the retainer 58 and 4 the reflector 60 serve as a free gyro unit and the reflector maintains a fixed reference even though the missile may pivot with respect to the reflector.

The antenna 16 as well as its alternator 56 are included in the system shown in Figure 3. Signals having a relatively high frequency are introduced to the antenna from a magnetron 62 when the magnetron is triggered by pulses produced at a relatively low repetition rate by a modulator 64. An input terminal of a range gate circuit 66 is also connected to the output terminal of the modulator 64 as well as to the output terminal of a receiver 68. Connections are made from an output terminal of the range gate circuit 66 and the output terminal of the magnetron 62 to input terminals of the receiver 68.

Two output signals having a 90 phase relationship to each other are produced by the alternator 56, as will be disclosed in detail hereafter. One of the quadrature signals is introduced to a transformer 70, which produces a pair of signals having a 180 phase relationship. Similarly, a transformer 72 converts the other quadrature signal from the alternator 56 into a pair of signals having a 180 phase relationship to each other. The output terminals of the transformers 70 and 72 are connected to input terminals of gated amplifiers 74 and 76 and gated amplifiers 78 and 80, respectively. Input terminals of the amplifiers 74, 76, 78 and 80 are also connected to an output terminal of the receiver 68.

The output signals from the amplifiers 74, 76, 78 and 8%} are introduced to detectors 82, 84, 86 and 88, respectively, which are paired so that a signal resolver 90 receives the output of the detectors 82 and 84 and a signal resolver 92 receives signals from the detectors 86 and 88. A difierentiator 94 and a servornechanism 96 are connected in cascade arrangement to the output terminal of the signal resolver 90, and a diflerentiator 98 and a servornechanism 100 are similarly connected to the signal resolver 92. The output terminals of the signal resolvers 90 and 92 may also be directly connected to the input terminals of the servomechanisms 96 and 100, respectively, as indicated by the broken lines in Figure 3.

Before the release of the missile, the antenna in the interceptor 12 is operated by the radar system 20 (Figure 10) so that it points continuously at the target. The antenna pivots in a plane of azimuth, corresponding to a right or left movement in a horizontal direction, and in a plane of elevation, corresponding to an up or down movement. The movement of the interceptor antenna in the azimuth or elevation'planes is converted by the system shown in Figure 10 into appropriate movements of the antenna 16 in the planes of the mount gimbal 28 and ring gimbal 30, as will be described in detail hereinafter. Such movements of the antenna 16 also cause it to continuously point at the target before the missile is released.

Upon the release of the missile, the solenoid 42 (Figure 2) is energized to disengage the pinion gear 44 from the ring gear 40. This causes the antenna 16 to be released for free pivotal movement relative to the missile in the planes of the ring gimbal 30 and horseshoe gimbal 32. As the missile travels towards the target 14, the modulator 64 (Figure 3) triggers the magnetron 62 at a predetermined rate and causes the magnetron to produce pulses of energy which are transmitted towards the target by the antenna 16. Since the reflector 60 (Figure 2) is slightly skewed with respect to the shaft 50 and the wave guide 52 and sincethe reflector is spun by the motor 54 at a predetermined speed relative to the shaft, the antenna transmits a beam which rotates about an axis at the speed of motor rotation. This beam has a conical shape in space, as indicated at 102 in Figure 7, for a complete revolution of the reflector and a conical shape, as indicated at 104, at any particular instant. The axis of the composite conical beam 102 is indicated at 106 in Figure 7,

If the missile is proceeding on a proper course towards the target, the target appears on the axis 106 of the composite cone 102. This causes the strength of each transmitted pulse of energy which falls on the target to be substantially constant and the strength of the pulses reflected from the target back to the antenna 16 to remain substantially constant. When the missile deviates from its proper course, however, the target no longer appears on the axis 106, and the strength of the beam falling on the target varies sinusoidally as the beam rotates through a complete revolution. The phase and amplitude of the sinusoidal signal are determined by the position of the target relative to the conical axis 106. For example, a sinusoidal envelope 108 in Figure 4 is produced by the reflected pulses when the target is at a position 110 in Fig. 7 relative to the conical axis 106, and a sinusoidal envelope 112 is produced by the reflected pulses with the target in a position 114. As will be seen, the envelope 112 has a greater amplitude and a different phase than the envelope 108.

The pulses reflected by the target 14 are received by the antenna 16 and are introduced through the receiver 68 (Figure 3) to the gated amplifiers 74, 76, 78 and 80. Only the pulses from the target 14 are introduced to the gated amplifiers as a result of the action of the range gate circuit 66, which opens the receiver for the passage of pulses only at the time that the pulses are expected from the target. The pulses introduced to the gated amplifiers are mixed in the amplifiers with the signals from the transformers 70 and 72. As previously disclosed, each of the transformers produces a pair of signals having a phase relationship of substantially 180 to each other and a phase relationship of substantially 90 to the signals from the other transformer. The phase relationships of the signals introduced to the amplifiers 74, 76, 78 and 80 from the transformers 70 and 72 are illustrated by the envelopes 116, 118, 120 and 122, respectively, in Figure 5.

The pulses reflected by the target 14 to the antenna 16 pass through each of the amplifiers 74, 76, 78 and 80 during substantially only half of the time, corresponding to the positive portion of each of the signals 116, 118, 120 and 122, respectively. The amplitude of the pulses passing through each amplifier at any instant is determined not only by the strength of the pulse as it is introduced to the amplifier but also by the amplitude at that instant of the sinusoidal signal introduced to the amplifier from either the transformer 70 or the transformer 72. The peak amplitude of the pulses passing through each of the amplifiers 74, 76, 78 and 80 determined by the detectors 82, 84, 86 and 88, respectively.

The signal resolver 90 operates on the signals passing through the detectors 82 and 84 to produce a resultant signal having a phase and an amplitude which control the movement of the missile in the horizontal direction. The resolver also shifts the phase of the resultant signal through an angle equal to the angle through which the missile has previously pivoted relative to the mount gimbal 28, as will be disclosed in detail hereafter. Such a phase shift is necessary because the rotation of the missile relative to the mount gimbal 28 causes the coordinates determined by the transformers 70 and 72 to become different from the coordinates represented by the fins 24 and 26. The angle through which the missile rotates at any instant relative to the mount gimbal 28 is illustrated in Figure 6 by the angular distance between each of the fins 24- and 26 in its solid and broken lines.

After being shifted in phase, the signal passing through the resolver 90 is differentiated by the diiferentiator 94, and this differentiated signal is either introduced directly to the servomechanism 96 or is combined with the phaseshifted signal from the signal resolver before being introduced to the servomechanism. A differentiated signal is produced to indicate the rate at which any deviations are being corrected and to prevent hunting as the deviation approaches zero. Upon the introduction of the difierentiated signal to the servomechanism 96, the servomechanism produces a pivotal movement of the fins 24. The pivotal movement of the fins in turn causes the missile to pivot relative to the ring gimbal 30, such that the missile returns to an optimum flight path relative to the target. When the missile returns to an optimum flight path relative to the target, the antenna 16 once again points directly at the target.

In like manner, the signal resolver 92 operates on the signals passing through the detectors 86 and 88 to produce a resultant signal which controls the pivotal movement of the missile on the horseshoe gimbal 32. The phase of the signal is shifted by the resolver through an angle corresponding to the prior rotation of the missile on the mount gimbal 28, and this phase-shifted signal is difierentiated and introduced after differentiation to the servomechanism 100. The servomechanism pivots the fins 26 which in turn cause the missile to pivot relative to the horseshoe gimbal 32.

Upon a pivotal movement of the missile relative to the horseshoe gimbal 32, a signal is produced in the synchro 48 (Figure 2) and is introduced to the motor 34. The motor 34 then rotates the missile 10 on the mount gimbal 28 until the signal from the synchro 48 is reduced to zero. At the same time, the missile pivots in a compensatory manner relative to the ring gimbal 30. This compensatory motion of the missile relative to the ring gimbal occurs because of the freedom of movement provided between the missile and the ring gimbal when the pinion gear 44 becomes disengaged from the ring gear 40 upon the release of the missile. Compensatory movements of the missile in the two substantially perpendicular planes represented by the mount gimbal 38 and the ring gimbal 30 provide a substitute for the movement of the missile in a third plane substantially perpendicular to the first two planes, this third plane being represented by the horseshoe gimbal 32.

The operation of the antenna 16 and the associated electrical system shown in Figure 3 causes the missile to follow a collision or other optimum course in which the missile gradually overtakes and finally intercepts a target 14. As may be seen in Figure 8, the missiie 10 has at any instant a velocity V and the target a velocity V The velocity V may be resolved into components V V and VM(3) of a coordinate system in which VM(1) is the component of velocity in the direction of a line of sight 126 (Figures 8 and 9) between the missile and the target and VM(2) and VM(3) are the components of velocity in directions substantially perpendicular to the line of sight 126.

Similarly, the velocity V may be resolved into components V VT(2) and V along axes corresponding to the above coordinates. In an ideal collision Since the only motion of the missile relative to the target is along the line of sight, the missile moves towards the target with a velocity V V and ultimately intercep'ts the target, as illustrated in Figure 9 for a particular flight path of the target.

The system shown in Figure 10 is adapted to provide a pivotal movement of the antenna 16 so that it points at the target before the missile is released. The system includes the radar system 20 adapted to provide indications in a conventional manner of the distance from the missile to the target along three substantially perpendicular axes. Thus, the radar system provides an indication of the azimuthal distance X from the missile; the elevational distance Y; and the horizontal distance Z from the missile to the plane formed by extending the X and Y axes through the target. The distances X, Y and Z are illustrated in Figure 11.

7 The indications of the distances Y, X and Z are amplified by amplifiers 130, 132, and 134, respectively. The outputs from the amplifiers 130 and 132 are introduced to a signal resolver 136 which acts upon the sigthe second input terminal of the amplifier 138. The

output from the amplifier 138 is introduced to a motor 142, which drives the signal resolver 136, a signal resolver 144 and a synchro 146 in accordance with the signal in-' troduced to it. The synchro 146 is in turn electrically connected to the synchro 48 in the missile to control the rotational movement of the antenna 16 on its mount gimbal 28 (Figure 2).

In addition to being connected to an input terminal of the signal resolver 136 (Figure 10), the output terminal ofthe amplifier 132 is connected to an input terminal of a signal resolver 150. The signal resolver 150 also receives signals from the signal resolver 144, the input terminal of which is connected to the output terminal of the amplifier 134. I Connections are made from output terminals of the resolver 150 to appropriate input terminals of an amplifier 152, the output from which is introduced to a motor 154 so that the motor will drive the resolver 150 and a synchro 156 in accordance with the signals from the amplifier 152. The synchro 156 is inturn electrically connected to the synchro 38 to provide a rotation of the antenna 16 on its ring gimbal 30 .(Figure 2) in accordance with signals from the synchro 156.

The signal resolvers 136, 144 and 150 may be similar to the resolvers disclosed on pages 340 to 343, inclusive,

in volume 17, Components Handbook, MIT Radiation Laboratory Series (1949 edition) and operate to produce output signals which are functions of signals introduced to the resolvers as will be disclosed in detail hereinafter.

The determinations by the radar system 20 (Figure 10) of the distances X and Y are utilized by the signal resolver 136 to determine the angle a through which the missile antenna 16 must rotate on its gimbal 28 to maintain the missile pointed at the target. As will be seen in Figure 11, the angle a may be determined by the relationship N is the leg common to the two interior triangles. Also,

I N=X cos a Subtracting Equation 3 from Equation 2,

Y. sin a-X cos a= (4) The signal resolver 136 acts to produce a signal indicative of the relationship Y sin aX cos a. The signal may be produced by a pair of rotatable windings disposed substantially" at right angles to each other and at an angle on to a pair of stationary windings. The signals in each of the rotatable windings are combined with the signals from the amplifiers 130 and 132 indicative of X and Y, respectively, to obtain an indication represented by Equation 4.

If the rotatable windings have rotated through an angle on with respect to their stationary windings, the signal produced by the resolver for operating the motor 142 is substantially zero. For a condition where the rotatable windings of the resolver 136 have not been driven through a proper angle a, the relationship Y sin u-X cos cc is not zero. An error signal is therefore produced in the amplifier 138 and this error signal is utilized by the motor 142 to drive the resolver 146 in a direction to reduce the signal amplitude. In this way, the resolver 136 and the synchro 146 are driven through an angle at. An error signal is in turn produced in the synchro 48 in case the synchro has rotated through a different angle than the synchro 146, and this signal is utilized by the motor 34 to rotate the mount gimbal 28 through an angle a similar to the angular rotation of the resolver 136. I If the missile is released from the interceptor at a relatively small distance from the target, the distances X and Y may be relatively small, even though the error angle on formed by these distances is relatively large. The relatively small distances X and Y may produce an in stability in the operation of the slaving system at a time when a maximum accuracy in training the antenna 16 on the target is desirable and often even necessary. A maximum accuracy is often necessary because of the relatively short time that the missile will have to correct any errors in its course after it is released.

To increase the stability in the operation of the slaving system, the resolver 136 produces, at a separate output terminal, a signal indicative of the value /X +Y This signal in amplified form controls the gain of the amplifier 138 so that the gain of the amplifier is greater for small values of X and Y than for larger values of these distances. Since the amplifier controls the operation of the motor 142, the sensitivity of the motor is effectively increased for decreases in X and Y.

Just as the missile antenna is rotated on its mount gimbal 28 in accordance with signals from the resolver 136, the antenna is pivoted on its ring gimbal 30 in accordance with signals from the resolver 150. As will be seen in Figure 11, the pivotal movement of the ring gimbal is determined by the angle Mathematically, 'y is given by the relationship:

NIP:

tan 7= where S is the hypotenuse of the right triangle formed by the distances X and Y as the legs and, further, where S and Z form the legs of a right triangle whose hypotenuse is the distance between the missile and the target.

But

The signal resolver 144 produces a signal proportional to Z cos or upon the introduction to it of the signal indicative of Z, since it rotates through an angle a in accordance with the operation of the motor 142. The signal from the resolver 144 is then combined in the reportional to solver 15tl with the amplified signal indicative of X to produce a resultant signal indicative of Z cos a sin -X cos 'y This signal is applied after amplification to the motor 154 to produce a rotation of the motor through the angle 7 so as to reduce the error signal from the resolver to zero.

The motor also drives the synchro 156 through the angle 7, and the synchro 156 in turn operates on the s'ynchro 38 to produce a rotation of the antenna 16 through an angle 7 on the ring gimbal 30. The operation of the resolver 150 and the motor 154 is stabilized by the production of a signal having an amplitude pro- This signal operates to increase the sensitivity of the amplifier 152, and therefore of the motor 154, for relatively small values of X and Z cos on.

There is thus provided a slaving system for operating, in conjunction with a radar system which determines the position of a rnissible relative to a target, to maintain the antenna of a missile pointed at a target before the missile is released. By pointing the missile antenna at the target before the missile is released, the missile is provided with as good a change as possible of intercepting the target after its release. 7

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

What is claimed is:

1. In combination in an interceptor for launching a missile to intercept a target, a missile antenna pivotable relative to the missile in a pair of substantially perpendicular planes so as to be pointed at the targetbefore the release of the missile, a radar system fordetermining the distance between the missile and the target, means operative upon the determination of distance to provide a first signal controlling the pivotal movement of the antenna in one of the two substantially perpendicular planes so as to train the antenna on the target, and means operative upon the determination of distance to provide a second signal controlling the pivotal movement of the antenna in the other of the two substantially perpendicular planes so as to train the antenna on the target.

2. In combination in an interceptor for launching a missile to intercept a target, a missile antenna pivotable relative to the missile in a pair of substantially perpendicular planes so as to be pointed at the target before the release of the missile, means for determining the distance between the missile and the target in a plurality of substantially perpendicular distance components, means for converting the determinations of distance into a first error signal indicative of the required angular rotation of the antenna relative to the missile in one of the two substantially perpendicular planes, means for rotating the antenna through the required angle of rotation in the first plane to minimize the error signal, means for converting the determinations of distance into a second error signal indicative of the required angular rotation of the antenna relative to the missile in the other of the two substantially perpendicular planes, and means for rotating the antenna through the required angle of rotation in the second plane to minimize the error signal.

3. In combination in an interceptor for launching a missile to intercept a target, a radar system for determining the distance between the missile and the target in a plurality of substantially perpendicular distance components, an antenna in the missile, means for providing a rotation of the antenna in a first plane, means for converting the determinations of distance into an error signal having an amplitude indicative, in accordance with a 1-0 predetermined trigonometric relationship, of any further required rotation of the antenna in the first plane, means for providing a rotation of the antenna in a second plane substantially perpendicular to the first plane, and means for converting the determinations of distance into an error signal having an amplitude indicative, in accordance with a predetermined trigonometric relationship, of any further required rotation of the antenna in the second plane. 4. In combination in an interceptor for launching a missile to intercept a target, a radar system for determining the distance between the missile and the target in a plurality of substantially perpendicular distance compo nents, an antenna in the missile, means for providing a rotation of the antenna in a first plane, means for providing a determination of the angular rotation of the antenna in the first plane, means for combining in a predetermined relationship the determinations of distance and the angular rotation of the antenna in the first plane to produce an error signal indicative of any angular movements required in the first plane to point the antenna at the target, means for rotating the antenna in the first plane in a direction to minimize the error signal, means for providing a rotation of the antenna in a second plane substantially perpendicular to the first plane, means for providing a determination of the angular rotation of the antenna in the second plane, means for combining in a predetermined relationship the determinations of distance and the angular rotation of the antenna in the second plane to produce an error signal indicative of any angular movements required in the second plane to point the antenna at the target, and means for rotating the antenna in the second plane in a direction to minimize the error signal.

5. In combination in an interceptor for launching a missile to intercept a target, a radar system in the interceptor operative to determine the distance between the interceptor and the target in a plurality of substantially perpendicular component distances, an antenna in the missile, amount gimbal forming part of the antenna and adapted to provide a rotational movement of the antenna relative to the missile, a ring gimbal mounted on the mount gimbal to provide a pivotal movement of the antenna relative to the missile, means operative in a predetermined manner in accordance with the determinations of distance and with prior movements of the antenna on its mount gimbal to produce a rotation of the antenna on its mount gimbal for maintaining the antenna pointed at the target, and means operative in a predetermined mannor in accordance with the determinations of distance and with prior movements of the antenna on its ring gimbal to produce a pivotal movement of the antenna on its ring gimbal for maintaining the antenna pointed at the target.

6. In combination in an interceptor for launching a missile to intercept a target, a radar system in the interceptor operative to determine the distance between the interceptor and the target in a plurality of substantially perpendicular distance components, an antenna in the missile, a mount gimbal forming a part of the antenna and adapted to provide a rotational movement of the antenna relative to the missile, a ring gimbal mounted on the mount gimbal to provide a pivotal movement between the antenna and the missile, means operative in accordance with a predetermined relationship between the angular rotation of the antenna on the mount gimbal and the determinations of distance to provide a first error signal indicative of any further antenna rotation required in the plane of the amount gimbal to point the antenna at the target, means operative to rotate the antenna on the mount gimbal in a direction to minimize the error signal, means operative in accordance with a predetermined relationship between the angular rotation of the antenna on the ring gimbal and the determinations of distance to provide a second error signal indicative of any further antenna rotation required in the plane of 1 1 the ring gimbal to point the antenna at the target, and means operative to rotate the antenna on the ring gimbal a direction to minimize the second error signal.

7 In combination in an interceptor for launching a missile to intercept a target, a radar system in the interceptor adapted to represent the distance between the missile and the target in a plurality of substantially perpendicular distance components, an antenna in the missile, a mount gimbal mounted on the antenna to provide a rotation of the antenna relative to the missile, a ring gimbal mounted on the mount gimbal to provide a pivotal movement of the antenna relative to the missile, a first resolver rotatable with the mount gimbal and operative in accordance with a predetermined trigonometric relationship involving its own angular rotation and the determinations of distance to provide a first error signal indicative of any further rotation required in the plane of the mount gimbal to maintain the antenna pointed at the target, means operative by the error signal to rotate the antenna and the resolver in a direction to minimize the signal, a second resolver pivotable with the ring gimbal and operative in accordance with a predetermined trigonometric relationship inVOlving its own angular rotation and the determinations of distance to 8. In combination in an interceptor for launching a missile to intercept a target, a radar system in the interceptor adapted to provide determinations of the distancebetween the missile and the target in a plurality of substantially perpendicular distance components, an antenna in the missile, a first gimbal in the antenna for providing a pivotal movement of the antenna relative to the missile in a first plane, a second gimbal mounted on the first gimbal to provide a pivotal movement of the antenna relative to the missile in a second plane substantially perpendicular to the first plane, a first signal resolver operative in accordance with a trigonometric function including the determination of distance and its own angular rotation to provide a first error signal indicative of any further rotation required in the first plane to maintain the antenna pointed at the target, first motive means operative in accordance with the error signal to rotate the antenna and the resolver in the first plane to minimize the error signal, a first amplifier associated with the resolver to vary the sensitivity in the operation of the motive means in accordance with the distance between the missile and the target, a second signal resolver operative in accordance with a trigonometric function including the determination of distance and its own angular rotation to provide a second error signal indicative of any further rotation required in the second plane to maintain the antenna pointed at the target, second motive means operative in accordance with the second error signal to rotate the antenna and the resolver in .the second plane to minimize the error signal, and a second amplifier associated with the resolver to vary the sensitivity in the operation of the second motive means in accordance with the distance between the missile and the target.

9. In combination in an interceptor for launching a missile to intercept a target, a radar system in the interceptor adapted to provide determinations of the distance between the missile and the target in a plurality of distance components disposed in substantially perpendicular directions, an antenna in the missile, a first gimbal in the antenna for providing a pivotal movement of the antenna relative to the missile in a first direction, a second gimbal mounted on the first gimbal to provide a pivotal movement of the antenna relative to the missile in a second direction substantially perpendicular to the first direction, a first signal resolver operative in accordance with a trigonometric function including the determination of distance and its own angular rotation to provide a first error signal indicative of any further rotation required in the resolver in the first direction to minimize the error signal, a first motor for driving the resolver in a direction to minimize the error signal, synchro means associated with the resolver and the motor for producing a second error signal having an amplitude dependent upon any differences between the rotation of the resolver and the pivotal movement of the antenna in the first direction, a second motor for pivoting the antenna relative to the missile on the first gimbal to minimize the second error signal, a second signal resolver operative in accordance with a trigonometric function including the determination of distance and its own angular rotation to provide a third error signal indicative of any further rotation required in the resolver in the second direction to minimize the error signal, a third motor for driving the second resolver in a direction to minimize the third error signal, synchro means associated with the resolver and the motor for producing a fourth error signal having an amplitude dependent upon any differences between the rotation of the resolver and the pivotal movement of the antenna in the second direction, and a fourth motor for pivoting the antenna relative to the missile on the second gimbal to minimize the fourth error signal.

References Cited in the file of this patent UNITED STATES PATENTS 2,512,693 Sparks June 27, 1950 2,557,401 Agins et a1. June 19, 1951 2,638,585 Priest May 12, 1953 

